Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Anticonvulsants and Antiparkinsonism Drugs Chapter 5

Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins

Anticonvulsants and Anticonvulsants and Antiparkinsonism Antiparkinsonism

DrugsDrugs

Anticonvulsants and Anticonvulsants and Antiparkinsonism Antiparkinsonism

DrugsDrugs

Chapter 5Chapter 5


Anticonvulsant DrugsAnticonvulsant DrugsAnticonvulsant DrugsAnticonvulsant Drugs

Prevent convulsions or seizure

Partial or focal seizure Arise from a localized area in the brain and cause specific

symptoms

Can spread to the entire brain and cause a generalized seizure

Generalized seizure Absence

Myoclonic

Tonic-clonic


Psychomotor SeizuresPsychomotor SeizuresPsychomotor SeizuresPsychomotor Seizures

Occur most often in children.

Aura may precede the event.

Most common motor symptom is drawing or jerking of the mouth and face.


EpilepsyEpilepsyEpilepsyEpilepsy

Permanent, recurrent seizure disorder


Actions of AnticonvulsantsActions of AnticonvulsantsActions of AnticonvulsantsActions of Anticonvulsants

Reduce the excitability of the neurons of the brain


Uses of AnticonvulsantsUses of AnticonvulsantsUses of AnticonvulsantsUses of Anticonvulsants

Used to control seizure activity, but often a patient will not respond well to one drug, and another drug or a combination will be tried

Dose adjustments often are needed to find the correct level of control


Adverse Reactions of AnticonvulsantsAdverse Reactions of AnticonvulsantsAdverse Reactions of AnticonvulsantsAdverse Reactions of Anticonvulsants

The most common adverse reaction is sedation.

Can range from drowsiness to somnolence

Agitation rather than sedation may occur in some patients.

Adverse reactions may be reduced or eliminated with therapy or a decrease in dose.


Adverse Reactions of AnticonvulsantsAdverse Reactions of AnticonvulsantsAdverse Reactions of AnticonvulsantsAdverse Reactions of Anticonvulsants Benzodiazepines also can cause sedation

Adverse reactions can be dose dependent and include:

Anorexia

Constipation or diarrhea

A health care provider should be notified if:

Unusual bruising or bleeding

Fever

Sore throat

Rash

Mouth ulcers



Hydantoins (phenytoin) are the most commonly prescribed anticonvulsants, and adverse effects include:

Nystagmus

Ataxia

Slurred speech

Mental changes

Gingival hyperplasia

Blood dyscrasias



Succinimides often cause gastrointestinal symptoms

Other adverse reactions:

Mental confusion

Personality changes

Pruritus

Urticaria

Urinary frequency

Weight loss

Hematologic changes



• Miscellaneous anticonvulsants

– Lamotrigine – severe and potentially fatal rash


Contraindications, Precautions, and Contraindications, Precautions, and Interactions of AnticonvulsantsInteractions of AnticonvulsantsContraindications, Precautions, and Contraindications, Precautions, and Interactions of AnticonvulsantsInteractions of Anticonvulsants

Care should be taken with barbiturate use in patients with liver, kidney, or neurologic disorders or pulmonary disease.

Barbiturates are used with caution in hyperactive children.

Barbiturates will have an additive effect if used with alcohol or other CNS depressants.



Care should be taken with benzodiazepine use in patients with psychoses, acute narrow angle glaucoma, liver or kidney disease, or neurologic disorders.

Benzodiazepines should be used with caution in elderly or debilitated patients.

Alcohol and other CNS depressants can also have an additive effect when used with benzodiazepine.

Benzodiazepines interact with a number of other medications.



Hydantoins are contraindicated in patients with:

Sinus bradycardia

Sinoatrial block

Second- and third-degree AV block

Adams-Stokes syndrome

Liver disease

Pregnancy and lactation



Hydantoins have an additive effect with alcohol and other CNS depressants.

Phenytoin should be used with caution in patients with:

Hypotension

Severe myocardial insufficiency

Hepatic impairment

Phenytoin interacts with many different drugs.



Succinimides are contraindicated in patients with bone marrow depression or hepatic or renal impairment and during lactation.

Additive effect with alcohol, antidepressants, and narcotics

Concurrent administration with other anticonvulsants may require a dosage adjustment.



Miscellaneous anticonvulsants are used cautiously in patients with:

Glaucoma or increased intraocular pressure

History of cardiac, renal, or liver dysfunction or psychiatric disorders

Carbamazepine

Contraindicated in patients with bone marrow suppression or hepatic or renal impairment

Interacts with several other drugs



Valproic acid

Contraindicated in patients with renal impairment

Oxcarbazepine

May exacerbate dementia

Lamotrigine

Interacts with valproic acid

Miscellaneous anticonvulsants have an additive effect when combined with CNS depressants and alcohol.


Patient Management Issues Patient Management Issues with Anticonvulsantswith AnticonvulsantsPatient Management Issues Patient Management Issues with Anticonvulsantswith Anticonvulsants

• Dosage adjustments may be necessary during initial treatment.

• Dosage adjustments are based on patient’s response and adverse reactions.

• Medication must be taken as prescribed.

– Do not omit or miss a dose.

– Do not abruptly discontinue.


Educating the Patient and Family Educating the Patient and Family About AnticonvulsantsAbout AnticonvulsantsEducating the Patient and Family Educating the Patient and Family About AnticonvulsantsAbout Anticonvulsants

Family may be the first to witness seizures.

Keep a record of all seizures.

Anticonvulsants control, but do not cure, epilepsy.

Support groups may be available.

Safety concerns may need to be addressed, such as driving or working conditions.



Do not increase, decrease, or omit dose.

Blood levels may need to be monitored.

Do not abruptly discontinue.

These drugs may cause drowsiness or dizziness.

Avoid alcohol.

Carry identification indicating drug use and type of seizures.

Do not use other medications without consulting a health care provider.



Hydantoins

Brush and floss

Make regular dental appointments for oral examination and care

Take with food

Shake the suspension before use



Succinimides

Take with food or milk to avoid gastrointestinal upset.


Antiparkinsonism DrugsAntiparkinsonism DrugsAntiparkinsonism DrugsAntiparkinsonism Drugs

• Parkinson disease – “paralysis agitans” is a degenerative disorder of the central nervous system

• Caused by a deficiency of dopamine and an excess of acetylcholine within the central nervous system


Actions of Dopaminergic DrugsActions of Dopaminergic DrugsActions of Dopaminergic DrugsActions of Dopaminergic Drugs

Affect the dopamine content of the brain

Dopamine is not effective when given orally since it does not cross the blood-brain barrier.

Levodopa will cross the blood-brain barrier and then converts to dopamine.


Uses of Dopaminergic DrugsUses of Dopaminergic DrugsUses of Dopaminergic DrugsUses of Dopaminergic Drugs

Treat signs and symptoms of parkinsonism

Levodopa is the gold standard.

Carbidopa is always given with levodopa.

Amantadine is less effective than levodopa but more effective than anticholinergics.


Adverse Reactions of Dopaminergic Adverse Reactions of Dopaminergic DrugsDrugsAdverse Reactions of Dopaminergic Adverse Reactions of Dopaminergic DrugsDrugs

Choreiform movements

Dystonic movements

Mental changes:

Depression

Psychotic episodes

Paranoia

Suicidal tendencies


Off–On PhenomenonOff–On PhenomenonOff–On PhenomenonOff–On Phenomenon

• Patient may suddenly alternate between improved clinical status and loss of therapeutic effect

• Associated with long-term levodopa treatment

• “Drug holiday” may be needed


Contraindications, Precautions, and Contraindications, Precautions, and Interactions of Dopaminergic DrugsInteractions of Dopaminergic DrugsContraindications, Precautions, and Contraindications, Precautions, and Interactions of Dopaminergic DrugsInteractions of Dopaminergic Drugs

Levodopa is contraindicated in patients with narrow-angle glaucoma and taking MAOIs.

Levodopa interacts with many different drugs.



Levodopa is used cautiously in patients with:

Cardiovascular disease

Bronchial asthma

Emphysema

Peptic ulcer disease

Renal or hepatic disease

Psychosis

Lactating patients



Selegiline is used cautiously in patients with psychosis, dementia, or excessive tremor.

Selegiline increases the effectiveness of levodopa when they are taken together.

Selegiline interacts with fluoxetine.



Amantadine is used cautiously in patients with:

Seizure disorders

Hepatic disease

Psychosis

Cardiac disease

Renal disease

Amantadine interacts with numerous other drugs.


Actions and Uses of Anticholinergic Actions and Uses of Anticholinergic DrugsDrugsActions and Uses of Anticholinergic Actions and Uses of Anticholinergic DrugsDrugs

Inhibit acetylcholine in the CNS

Used as adjunctive therapy in all forms of parkinsonism

Control drug-induced extrapyramidal disorders


Adverse Reactions of Anticholinergic Adverse Reactions of Anticholinergic DrugsDrugsAdverse Reactions of Anticholinergic Adverse Reactions of Anticholinergic DrugsDrugs Dry mouth

Blurred vision

Dizziness

Mild nausea

Nervousness


Contraindications, Precautions, and Contraindications, Precautions, and Interactions of Anticholinergic DrugsInteractions of Anticholinergic DrugsContraindications, Precautions, and Contraindications, Precautions, and Interactions of Anticholinergic DrugsInteractions of Anticholinergic Drugs

Contraindicated in patients with:

Glaucoma

Pyloric or duodenal obstruction

Peptic ulcers, prostatic hypertrophy

Achalasia

Myasthenia gravis

Megacolon


Contraindications, Precautions, and Contraindications, Precautions, and Interactions of Anticholinergic DrugsInteractions of Anticholinergic DrugsContraindications, Precautions, and Contraindications, Precautions, and Interactions of Anticholinergic DrugsInteractions of Anticholinergic Drugs

Use with caution in:

Older adults

Cardiovascular disease (tachycardia, cardiac arrhythmias, hypertension, hypotension)

Urinary retention

Decreased liver or kidney function

Obstructive disease of the gastrointestinal tract


Actions and Uses of COMT InhibitorsActions and Uses of COMT InhibitorsActions and Uses of COMT InhibitorsActions and Uses of COMT Inhibitors

Catechol-O-methyltransferase (COMT) inhibitor

Thought to prolong the effect of levodopa by blocking the enzyme COMT, which would otherwise eliminate the dopamine

Used as an adjunct to levodopa/carbidopa

Easily crosses blood-brain barrier


Adverse Reactions of COMT InhibitorsAdverse Reactions of COMT InhibitorsAdverse Reactions of COMT InhibitorsAdverse Reactions of COMT Inhibitors

Disorientation and confusion

Light-headedness

Dizziness

Dyskinesias

Hyperkinesias

Nausea and vomiting

Hallucinations

Fever


Contraindications, Precautions, and Contraindications, Precautions, and Interactions of COMT InhibitorsInteractions of COMT InhibitorsContraindications, Precautions, and Contraindications, Precautions, and Interactions of COMT InhibitorsInteractions of COMT Inhibitors

Contraindicated during lactation

Associated with liver damage and liver failure

Used with caution in patients with hypertension, hypotension, and decreased hepatic or renal function


Actions and Uses of Dopamine Receptor Actions and Uses of Dopamine Receptor AgonistsAgonistsActions and Uses of Dopamine Receptor Actions and Uses of Dopamine Receptor AgonistsAgonists

Exact mechanism not understood

May mimic the effects of dopamine in the brain

Used for Parkinson disease


Adverse Reactions of Dopamine Receptor Adverse Reactions of Dopamine Receptor AgonistsAgonistsAdverse Reactions of Dopamine Receptor Adverse Reactions of Dopamine Receptor AgonistsAgonists

Nausea

Dizziness

Postural hypotension

Hallucinations

Somnolence

Vomiting

Confusion

Visual disturbances

Abnormal involuntary movements

Headache


Contraindications, Precautions, and Contraindications, Precautions, and Interactions of Dopamine Receptor Interactions of Dopamine Receptor AgonistsAgonists


Contraindicated in patients with severe ischemic heart disease or peripheral vascular disease

Use with caution in patients with:

Dyskinesia

Orthostatic hypotension

Hepatic or renal impairment

Cardiovascular disease

History of hallucinations or psychosis




Increased risk of CNS depression

Increase the effects of levodopa when coadministered

Interact with ciprofloxacin and phenothiazines

Pramipexole interacts with a number of medication

Ropinirole interacts with estrogens


Patient Management Issues with Patient Management Issues with Antiparkinsonism DrugsAntiparkinsonism DrugsPatient Management Issues with Patient Management Issues with Antiparkinsonism DrugsAntiparkinsonism Drugs

History obtained from patient can be unreliable.

Baseline physical assessment needed.

Drug therapy needs careful monitoring.

Some patients communicate poorly.

Observe the patient for outward changes that may indicate adverse reactions.

Symptoms may be communicated through changes in posture and facial expression.


Educating the Patient and Family Educating the Patient and Family About Antiparkinsonism DrugsAbout Antiparkinsonism DrugsEducating the Patient and Family Educating the Patient and Family About Antiparkinsonism DrugsAbout Antiparkinsonism Drugs

The home environment must be examined to make it least likely to result in accidents or falls.

Medication should be taken as prescribed.

Sudden changes in behavior can indicate hallucinations, depression, or other psychotic episodes.

Observe the patient for adverse reactions.

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Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Anticonvulsants and Antiparkinsonism Drugs Chapter 5